Rotating flame treater

ABSTRACT

An elongated article, such as pipe, is moved through first and second concentrically mounted cylindrical sleeves. The inner sleeve is secured to a support frame while the second sleeve is rotatably mounted on the inner sleeve and extends beyond the inner sleeve to support a gas burner for flame treating the exterior surface of the article. The inner sleeve is provided with an annular groove while the outer sleeve has a mating passageway. The inner sleeve has a passageway connecting the annular groove to a gas supply conduit. The outer sleeve is provided with a conduit connecting the mating passageway to the gas burner. Means can be provided to extrude, flame treat and print the article in a continuous process.

nited States Patent 1191 Shofner et al.

1 51 May 28, 1974 ROTATING FLAME TREATER Assignee: Phillips Petroleum Company, Bartlesville, Okla.

Filed: Apr. 23, 1973 Appl. No.: 353,506

[56] References Cited UNITED STATES PATENTS 3/1926 Bardeen 432/184 5/1956 Kreidl 264/80 8/1957 Lecluyse et a1 264/80 Seefluth 425/446 Hitter 432/124 Primary Examiner-John J. Camby Assistant Examiner-Henry C. Yuen [57] ABSTRACT An elongated article, such as pipe, is moved through first and second concentrically mounted cylindrical sleeves. The inner sleeve is secured to a support frame while the second sleeve is rotatably mounted on the inner sleeve and extends beyond the inner sleeve to supporta gas burner for flame treating the exterior surface of the article. The inner sleeve is provided with an annular groove while the outer sleeve has a mating passageway. The inner sleeve has a passageway connecting the annular groove to a gas supply conduit. The outer sleeve is provided with a conduit connecting the mating passageway to the gas burner. Means can be provided to extrude, flame treat and print the article in a continuous process.

10 Claims, 4 Drawing Figures r l ROTATING FLAME TREATER This invention relates to means for flame treating the surface of an article. In a specific aspect the invention relates to means for rotating a flame around the circurnference of a plastic pipe as it is being extruded.

Various means are known for flame treating the surface of an article of thermoplastic material for improving the adhesion thereto .of paint or ink or the like. However, some of these do not provide the degree of uniformity desired, while others are complicated in construction and operation. In flame treating extrudates, such as pipe, it is common to employ a ring heater which provides a 360 curtain of flame. However, slow extrusion rates make the use of such ring heaters undesirable because of excessive exposure of the extrudate surface to the flame.

Accordingly, it is an object of the invention to provide a new and improved means for flame treating a surface. Another object of the invention is to provide a simple device for flame treating the exterior surface of pipe as the pipe is being extruded. Yet another object of the invention is to provide means for flame treating only a portion of the exterior surface of pipe or other extrudate. A further object of theinvention is to provide the desired degree of flame treatment of an extrudate even at lowv extrusion rates. Other objects, aspects, and advantages of the invention will become apparent to those skilled in the art.

In the drawings,

FIG. 1 is a front elevational view of a pipe extruding, flame treating, and printing'system incorporating the present invention;

FIG. 2 is a front elevational view in cross section of the flame treater of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2; and

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2.

Pipe 11 of synthetic thermoplastic polymeric material, such as polyethylene, is extruded through die 12 by extruder 13. The extruded pipe 11 passes through flame treater l4 and printing unit 15 and between takeoff rolls I6 and 17. The flame treater 14 comprises a base 18, a vertical support member 19, a stationary cylindrical sleeve member 21 and a rotating cylindrical sleeve member 22. Vertical support member 19 has a circular opening 23 therein which is larger than the maximum transverse dimension of the pipe being processed. Cylindrical sleeve 21 has an internal diameter at least as great as the diameter of opening 23, and is welded to support member 19 with the opening 23 and sleeve 21 being at least substantially coaxial. The upstream section 24 of sleeve 21 has a reduced external diameter, which is only slightly smaller than the internal diameter of the-dwnstream portion of sleeve 22, permitting sleeve '22 to be mounted on the upstream portion of sleeve 21 for rotation thereabout. Sleeve 22 is provided with an annular spur gear 25, the teeth of which are engaged by drive chain 26 for the rotation of sleeve 22 by motor 27.

Sleeve 22 is provided with grooves 28, 29 and 30 in the inner surface of the downstream portion thereof, while the upstream section 31 of sleeve 22 has an enlarged internal diameter. Sealing means, such as 0- rings 32 and 33, are positioned in grooves 29 and 30, while annular bearings 34 and 35 are located in groove 28 and the downstream portion of section 31 of sleeve 22. Sleeve 21 is provided with an external annular shoulder 40 at thedownstream end of the upstream section 24. The downstream end of the upstream section 31 of sleeve 22 is downstream of the upstream end of sleeve 21 and forms an internal annular shoulder with the upstream section of sleeve 22. An annular ring 36 is secured to the upstream end of sleeve 21 to hold bearing 35 against shoulder 50, thereby holding sleeve 22 in place on sleeve 21.

The upstream section 24 of sleeve 21 is provided with an annular groove 41 in the exterior surface thereof. Groove 41 lies in a plane perpendicular to the longitudinal axis of sleeves 21 and 22. A passageway 42 in sleeve 21 provides fluid communication between gas supply pipe 43 and groove 41. A gas burner 44 is positioned inside'the upstream section of sleeve 22 in such a manner that the flame 45 is directed toward the exterior surface of pipe 11. Burner 44 can be adjustably mounted on sleeve 22 to permit modifications in the extent to which burner 44 extends radially toward the longitudinal axis of sleeve 22, thus permitting the equipment to be employed with various diameters of pipe ll.'A conduit 46 extends from burner44 to a passageway 47 which extends through sleeve 22 at a point adjacent groove 41 in sleeve 21. Passageway 47 is exposed to groove 41 throughout the rotation of sleeve 22 about sleeve 21. Thus, sleeve 22 and burner 44 can be rotated about the axis of pipe 11, while gas is continuously supplied to burner v44 by way of supply conduit 43, passageway 42, annular groove 41, passageway 47 and conduit 46.

The flame 45 contacts only a small portion of the exterior of pipe 11 at a given time, but the rate of rotation of sleeve 22 can be correlated with the rate of extrusion of pipe 11 to provide a'spiral path of the burner 44 about the longitudinal axis of pipe 11 such that the adjacent portions of the path of the contact of flame 45 and pipe '1] meet or overlap to provide a flame treatment of the entire exterior surface of pipe 11. If it is decided to flame treat only a portion of the exterior surface of pipe 11, the rotation rate for sleeve 22 can be slowed so that the helical steps of the flame. path do not overlap.

While the invention has'been illustrated with cylindrical pipe or tubing 11, it can be employed with a solid cylindrical extrudate as well as with tubular or solid extrudates having a cross section other than circular. For noncircular extrudates, it would generally be desirable to employ a cam and cam follower to move burner 44 inwardly and outwardly in accordance with the configuration of the extrudate as the sleeve 22 is rotated about the axis of the extrudate. While the invention has been described, for purposes of simplicity, in terms of upstream and downstream sections with reference to the direction of movement of the article being treated, it is obvious that the article could be passed through the flame treating mechanism in either direction.

Reasonable variations and modifications are possible within the scope of the foregoing disclosure and the appended claims to the invention.

That which is claimed is:

1. Apparatus for flame treating the exterior surface of a longitudinally elongated article, which comprises a support framework having a support member, a first cylindrical sleeve mounted on said support member and having an internal diameter greater than the maximum transverse direction of said article so that said article can be moved along its longitudinal axis through said first sleeve, a second cylindrical sleeve having a first end section which has an internal diameter slightly greater than the exterior diameter of at least a first end section of said first sleeve and mounted coaxially with and surrounding said first end section of said first sleeve for rotation of said second sleeve about the common axis of said first end section of said first sleeve and said second sleeve, said second sleeve having a second end section extending beyond said first sleeve, a gas burner mounted in the interior of said second end section of said second sleeve at a point beyond said first sleeve and directed inwardly toward said article as said article moves through said first and second sleeves, said first sleeve having an annular groove in the exterior surface of the first end section of said first sleeve and underlying the first end section of said second sleeve, said second sleeve having a passageway extending through said second sleeve with the inner end of said passageway being exposed to said groove throughout the rotation of said second sleeve about said common axis, first and second annular sealing means positioned between said first and second sleeves on opposite sides of said annular groove, conduit means associated with said second sleeve providing fluid communication between said passageway and said gas burner, a gas supply conduit, said first sleeve having means for providing fluid communication between said gas supply conduit and said annular groove, and means for rotating said second sleeve about said common axis.

2. Apparatus in accordance with claim 1 wherein said first and second sealing means are O-rings positioned in annular grooves in one of the opposing surfaces of said first and second sleeves, and wherein said groove lies in a plane perpendicular to said common axis.

3. Apparatus in accordance with claim 1 further comprising means for extruding said elongated article, means for printing on the exterior surface of said elongated article, and means for pulling said article from said extruding means through said first and second.

sleeves and then through said printing means.

4. Apparatus in accordance with claim 1 wherein said burner is adjustably mounted on said second sleeve.

5. Apparatus in accordance with claim 1 further comprising an exterior annular shoulder on said first sleeve at the joinder of the first end section of said first sleeve and the second end section of said first sleeve, the outer end of the first end section of said second sleeve having an annular bearing groove in the internal surface thereof, first annular bearing means mounted in said annular bearing groove in the end of said second sleeve between said second sleeve and said external annular shoulder, the joinder of the first and second end sections of said second sleeve forming an internal shoulder, second annular bearing means mounted ad jacent said internal shoulder, and means on the first end of said first sleeve for retaining said second bearing means against said internal shoulder.

6. Apparatus in accordance with claim 1 wherein said means for rotating said second sleeve comprises an annular spur gear mounted on the exterior surface of said second sleeve, a motor, and a drive chain engaging said spur gear and driven by said motor.

7. Apparatus in accordance with claim 6 wherein said first and second sealing means are O-rings positioned in annular grooves in one of the opposing surfaces of said first and second sleeves, and wherein said groove lies in a plane perpendicular to said common axis.

8. Apparatus in accordance with claim 7 further comprising means for extruding said elongated article, means for printing on the exterior surface of said elongated article, and means for pulling said article from said extruding means through said first and second sleeves and then through said printing means.

9. Apparatus in accordance with claim 8 further comprising an exterior annular shoulder on said first sleeve at the joinder of the first end section of said first sleeve and the second end section of said first sleeve, the outer end of the first end section of said second sleeve having an'annular bearing groove in the internal surface thereof, first annular bearing means mounted in said annular bearing groove in the end of said second sleeve between said second sleeve and said external annular shoulder, the joinder of the first and second end sections of said second sleeve forming an internal shoulder, second annular bearing means mounted adjacent said internal shoulder, and means on the first end of said first sleeve for retaining said second bearing means against said internal shoulder.

10. Apparatus in accordance with claim 9 wherein said burner is adjustably mounted on said second sleeve. 

1. Apparatus for flame treating the exterior surface of a longitudinally elongated article, which comprises a support framework having a support member, a first cylindrical sleeve mounted on said support member and having an internal diameter greater than the maximum transverse direction of said article so that said article can be moved along its longitudinal axis through said first sleeve, a second cylindrical sleeve having a first end section which has an internal diameter slightly greater than the exterior diameter of at least a first end section of said first sleeve and mounted coaxially with and surrounding said first end section of said first sleeve for rotation of said second sleeve about the common axis of said first end section of said first sleeve and said second sleeve, said second sleeve having a second end section extending beyond said first sleeve, a gas burner mounted in the interior of said second end section of said second sleeve at a point beyond said first sleeve and directed inwardly toward said article as said article moves through said first and second sleeves, said first sleeve having an annular groove in the exterior surface of the first end section of said first sleeve and underlying the first end section of said second sleeve, said second sleeve having a passageway extending through said second sleeve with the inner end of said passageway being exposed to said groove throughout the rotation of said second sleeve about said common axis, first and second annular sealing means positioned between said first and second sleeves on opposite sides of said annular groove, conduit means associated with said second sleeve providing fluid communication between said passageway and said gas burner, a gas supply conduit, said first sleeve having means for providing fluid communication between said gas supply conduit and said annular groove, and means for rotating said second sleeve about said common axis.
 2. Apparatus in accordance with claim 1 wherein said first and second sealing means are O-rings positioned in annular grooves in one of the opposing surfaces of said first and second sleeves, and wherein said groove lies in a plane perpendicular to said common axis.
 3. Apparatus in accordance with claim 1 further comprising means for extruding said elongated article, means for printing on the exterior surface of said elongated article, and means for pulling said article from said extruding means through said first and second sleeves and then through said printing means.
 4. Apparatus in accordance with claim 1 wherein said burner is adjustably mounted on said second sleeve.
 5. Apparatus in accordance with claim 1 further comprising an exterior annular shoulder on said first sleeve at the joinder of the first end section of said first sleeve and the second end section of said first sleeve, the outer end of the first end section of said second sleeve having an annular bearing groove in the internal surface thereof, first annular bearing means mounted in said annular bearing groove in the end of said second sleeve between said second sleeve and said external annular shoulder, the joinder of the first and second end sections of said second sleeve forming an internal shoulder, second annular bearing means mounted adjacent said internal shoulder, and means on the first end of said first sleeve for retaining said second bearing means against said internal shoulder.
 6. Apparatus in accordance with claim 1 wherein said means for rotating said second sleeve comprises an annular spur gear mounted on the exterior surface of said second sleeve, a motor, and a drive chain engaging said spur gear and driven by said motor.
 7. Apparatus in accordance with claim 6 wherein said first and second sealing means are O-rings positioned in annular grooves in one of the opposing surfaces of said first and second sleeves, and wherein said groove lies in a plane perpendicular to said common axis.
 8. Apparatus in accordance with claim 7 further comprising means for extruding said elongated article, means for printing on the exterior surface of said elongated article, and means for pulling said aRticle from said extruding means through said first and second sleeves and then through said printing means.
 9. Apparatus in accordance with claim 8 further comprising an exterior annular shoulder on said first sleeve at the joinder of the first end section of said first sleeve and the second end section of said first sleeve, the outer end of the first end section of said second sleeve having an annular bearing groove in the internal surface thereof, first annular bearing means mounted in said annular bearing groove in the end of said second sleeve between said second sleeve and said external annular shoulder, the joinder of the first and second end sections of said second sleeve forming an internal shoulder, second annular bearing means mounted adjacent said internal shoulder, and means on the first end of said first sleeve for retaining said second bearing means against said internal shoulder.
 10. Apparatus in accordance with claim 9 wherein said burner is adjustably mounted on said second sleeve. 